1. Field of the Invention
The present invention relates to a solar energy generating system, and more particularly, to a method and an apparatus for generating a current command value for tracking a maximum power point in the solar energy generating system.
2. Description of the Related Art
In general, a solar energy generating system is a system for converting light energy into electrical energy by using solar cells. FIG. 1 illustrates a general layout of a solar energy generating system, including a flyback converter. Referring to FIG. 1, power converters 20, such as flyback converters, are connected to solar cell modules 10, and a power grid 30 is connected to output terminals of the power converters 20.
As for the solar cell module 10 employed in this solar energy generating system, as shown in FIG. 2(a) and FIG. 2(b), the amount of maximum power generated and the generation conditions thereof (maximum power point 11) are varied, according to the amount of available solar radiation and ambient temperature. That is, as shown in FIG. 2(a), the maximum power point 11 of the solar cell module 10 rises with an increase in the amount of available solar radiation, and falls with an increase in ambient temperature. Therefore, the power converter 20 such as flyback converter should be designed to output the maxim available amount of power at all times, even when environmental conditions are varied.
In addition, the power converter 20 of the solar energy generating system of the related art needs a separate current detector for detecting current from the solar cell module 10 other than a voltage detector for detecting voltage of the solar cell module 10, in order to track the maximum power point of the solar cell module 10. This causes an increase in the total costs of the solar energy generating system and a complexity of the circuits thereof.